Thin film coatings on transparent substrates and methods of making and using thereof

ABSTRACT

Disclosed are transparent articles having a substrate adapted for carrying a transparent and electrically conductive thin film thereon. The thin film includes an optical matching-stress releasing layer directly deposited on the substrate; a first antireflection layer directly deposited on the optical matching layer; a metal layer adapted for infra-red reflection and electrical conductivity directly deposited on the first antireflection layer; a second antireflection layer deposited directly on the metal layer adapted for high visibility and infra-red transmission, and an optionally visible and infra-red region transparent outermost protective layer deposited on the second antireflection layer. In certain aspects, no buffer layer is positioned between the metal layer adapted for infra-red reflection and electrical conductivity and the second antireflection layer. The transparent articles have various uses including electrodes used in electrochromic devices and as glass treatments due to unique transparent, transmissive, and reflective properties.

TECHNICAL FIELD

The present invention generally relates to the field of thin filmcoatings, and more particularly, to thin film coatings on transparentsubstrates having anti-solar, low emissivity, and/or electricallyconductive properties.

BACKGROUND

FIG. 1A depicts a conventional thin film coating system 10 (e.g. lowemissivity coating systems) that utilizes a first antireflection layer30 (first dielectric layer) deposited directly on a surface of atransparent substrate 20, followed by a metal layer 40 deposited on thefirst antireflection layer 30, a buffer layer 50 deposited on the metallayer 40, and then a second antireflection layer 60 (second dielectriclayer) deposited on the buffer layer 50. In these conventional systems10, the thickness of the metal layer 40 is selected to provideadequately low emissivity while maintaining sufficiently hightransmittance of visible light to meet the requirements of the intendedapplication. The thickness of the first and second antireflection layers30, 60 is typically selected to achieve adequate anti-reflectance forthe metal film while the entire multi-layer coating on the substratepreferably exhibits high transparency to visible light and highreflectance to infrared. FIG. 1B further depicts another conventionalthin film coating system 90 that is very similar to FIG. 1A but thiscoating system 90 further includes a second metal layer, a second bufferlayer, and a third (outermost) antireflection layer. The thin filmcoating system shown in FIG. 1B is commonly referred to as a doublelow-e (low emissivity coating systems).

As alluded to above and where the metal layer 40 employs silver or otherhigh conductivity metal(s) (e.g., Ag, Au, Ag—Au, Cu, Al, Pd, etc.), abuffer layer 50 of Ni, Cr, Ti, Ni—Cr, or Si as disclosed in U.S. Pat.No. 6,040,939, is typically deposited over metal layer 40. Buffer layer50 may interact with and oxidize during the deposition of the secondantireflection layer 60, thereby forming an oxidized layer of, forexample, Ni, Cr, Ti, Si, or Ni—Cr. However, buffer layer 50 to reducesand/or inhibits the reaction of oxygen or other reactive gas with themetal layer 40 during deposition of the second antireflection layer 60.Thus, buffer layer 50, in theory, reduces and/or prevents oxidation ofmetal layer 40, which in turn preserves anti-solar, low emissivity, andelectrically conductive properties of these conventional films 10.

Although these conventional thin film coating systems 10 have numeroususes in industry such as coatings on window panes and/or as electrode(s)in dynamic optical films like electrochromic device(s), liquid crystalpanels, electrodes for photovoltaic devices, light emitting devices(LED, OLED), and radio frequency shielding applications variousdifficulties have been encountered by those skilled in the art whenmaking and/or using these conventional coating systems 10. Inparticular, it has proved difficult to achieve low emissivity coatingswhich also provide good attenuation of direct solar radiation, that is,good anti-solar properties. Furthermore, these conventional coatingsystems 10 have a limited shelf life in which a coated surface can onlybe exposed to air for days (or in some instances only hours) withoutsubstantial degradation of film quality due to, for example, migrationof oxygen or moisture from the atmosphere into the coating therebyreacting with the coated materials, which degrades the coating's uniformappearance, anti-solar properties, low emissivity properties,electrically conductive properties, or any combination thereof.Furthermore, because these conventional systems 10 require deposition ofan uniform buffer layer 50 over the metal layer 40 before deposition ofthe second antireflection layer 60, increased time, materials, andcomplexity are required when applying these coating systems on desiredsurfaces.

To further evidence this fact, these coating systems are frequentlydeposited (e.g., via sputter or e-beam deposition) on, for example,glazed window panels. In this regard, substantial manufacturing processcomplexity and production waste occurs when the sputtered multi-layercoating 10 on a glazing panel (e.g. substrate 20) deterioratessignificantly if it is not immediately laminated or otherwise assembledinto a multi-pane window to protect the coating from exposure to air.

BRIEF SUMMARY

Therefore, a need exists to provide transparent articles that overcomethe above mentioned problems. Accordingly, the transparent articlesdisclosed herein preferably exhibit anti-solar, low emissivity, and/orelectrically conductive properties and can be preferably storedindefinitely while concurrently maintaining high environmental stabilityand durability for years without needing to be immediately laminatedand/or assembled into a multi-pane window assemblies, thus avoidingdegradation issues exhibited by conventional thin film coating systems.In other words, the disclosed transparent articles have high durabilityand are not easily degraded at ambient humidity and/or room temperature.The transparent articles disclosed herein can be foamed on transparentflexible, rigid flat, textured surfaces, or fabrics. In certain aspects,the transparent articles are flexible and/or rollable (e.g., rolling ona cylinder of a roll to roll coater, and/or 1 cm radius, 0.75 cm, or 0.5cm, of curvature) without losing conductive performance, and thedisclosed thin films/coatings disclosed herein are heatable up to 500°C. without losing electrical conductance.

Specifically disclosed herein are transparent articles including asubstrate adapted for carrying a transparent and electrically conductivethin film thereon, the thin film includes an optical matching, adhesionpromoting, stress releasing layer (also referred to herein as the“optical matching stress releasing layer), a first antireflection layer,a metal layer adapted for infra-red reflection and electricalconductivity, and a second antireflection layer; the optical matching,adhesion promoting, stress releasing layer is directly deposited on thesubstrate at a thickness ranging from 1000 Å to 10,000 Å; the firstantireflection layer is directly deposited on the optical matching,adhesion promoting, stress releasing layer at a thickness ranging from100 Å to 1000 Å; the metal layer adapted for infra-red reflection andelectrically conductive film is directly deposited on the firstantireflection layer at a thickness ranging from 50 Å to 400 Å; thesecond antireflection layer is directly deposited on the metal layeradapted for infra-red reflection at a thickness ranging from 100 Å to1000 Å, and optionally an outermost protective transparent layer isdeposited on the second antireflection layer at a thickness ranging from100 Å to 10,000 Å. The disclosed transparent article has no buffer layerpositioned between the metal layer adapted for infra-red reflection andelectrical conductivity and the second antireflection layer. In certainaspects, a third antireflection layer is directly deposited on thesecond antireflection layer at a thickness ranging from 100 Å to 1000 Å,the third antireflection layer is preferably made from the same materialand has substantially the same thickness as the first antireflectionlayer (the total thickness of the second and third AR layers ispreferably approximately double the thickness of first antireflectionlayer), a second metal layer adapted for infra-red reflection andelectrical conductivity is directly deposited on the thirdantireflection layer at a thickness ranging from 50 Å to 400 Å; and afourth antireflection layer that is directly deposited on the secondmetal layer adapted for infra-red reflection at a thickness ranging from100 Å to 1000 Å, the fourth antireflection layer made from the samematerial and having substantially the same thickness as the secondantireflection layer—with the proviso that no buffer layer is depositedbetween the second metal layer and the fourth antireflection layer. Incertain embodiments, the outermost protective transparent layer isdirectly deposited on the fourth antireflection layer at a thicknessranging from 100 Å to 10,000 Å.

In certain aspects, the article has an optical transparency of at least30% between a wavelength ranging from 380 nm to 780 nm and has at least30% of total solar reflectance of heat rejection at a wavelength rangingfrom 380 nm to 2200 nm. In certain aspects, an optical transparency ofat least 40%, at least 50% or at least 60% between a wavelength rangingfrom 380 nm to 780 nm and has at least 40%, at least 50%, or at least60% of total solar reflectance of heat rejection at a wavelength rangingfrom 380 nm to 2200 nm. The article may further have a sheet resistanceranging from 1.2 Ohm/square to 120 Ohm/square.

In certain aspects, the first and second antireflection layersindependently include at least one of W or oxides thereof (e.g., WO₃),Sn or oxides thereof (e.g., SnO₂), Zn or oxides thereof (e.g., ZnO), Tior oxides (e.g., TiO2) or nitrides thereof, Al or oxides thereof, Ta oroxides thereof (e.g., Ta₂O₅), Hf or oxides thereof, Nb or oxidesthereof, an indium tin oxide (ITO), Bi or oxides thereof (e.g., Bi₂O₃),Ce or oxides thereof, Pr or oxides thereof, Ni or oxides thereof,aluminum doped zinc oxide (AZO), or indium doped zinc oxide (IZO).

In certain aspects, the first and second antireflection layers of thearticle each comprise W or oxides thereof.

In certain aspects, the first antireflection layer of the article isWO₃. In certain aspects, the second antireflection layer of the articleis W and WO₃.

In certain aspects, the first antireflection layer of the article isWO₃. In certain aspects, the second antireflection layer of the articleis WO₃.

In certain aspects, the metal layer adapted for infra-red reflection andelectrical conductivity comprises at least one of Ag, Au, Ag—Au, Pt, Cu,Al, Ti, Pd, Ni, Rd, or Zn. In certain aspects, the metal layer adaptedfor infra-red reflection and electrical conductivity is Ag.

In certain aspects, the substrate includes at least one of glass,polymer materials may be used including polycarbonate film(s), polyesterfilm(s) including a polyethylene terephthalate film (e.g., Melinex®manufactured by DuPont Teijin Films), and/or Fluorocarbon andfluorohydrocarbon materials. Representative organic polymers includepolyesters such as poly(ethyleneterephthalate) (“PET”), polycarbonates,polyacrylates and methacrylates such as poly(methylmethacrylate)(“PMMA”), poly(methacrylate), poly(ethylacrylate) and copolymers such aspoly(methylmethacrylate-co-ethylacrylate). Fluorocarbon polymers such asTeflon® can be used as well. Other polymers have indices of refractionbelow that of the antireflection coatings may be used, if desired.

In certain aspects, the transparent and electrically conductive thinfilm maintains, without loss, optical and electrical properties for upto nine years when stored at ambient humidity and/or room temperature.

In certain aspects, each of the optical matching, adhesion promoting,stress releasing layer, the first antireflection layer, the metal layer,and the second antireflection layer are uniformly deposited in thearticle.

In certain aspects, the outermost protective transparent layer ispresent in the article, the outermost protective transparent layer mayinclude a poly(p-xylylene) outer coating (e.g., Parylene C Parylene N,Parylene F). In certain aspects, the outermost protective transparentlayer ranges in thickness from 1,000 Å to 10,000 Å, and more preferably500 Å to 5,000 Å, and is transparent in the spectral region measuredfrom 0.35 μm to 25 μm. In certain aspects, it is preferable that theoutermost protective transparent layer is highly durable, washable withDI water, and/or air blow dryable. The outermost protective transparentlayer is also inert for cleaning solutions, such as alcohol, detergent,and ammonia in which the outermost protective layer may be contactedwith cleaning solutions and gently rubbed with a microfiber cloth. It isa hydrophobic material so forms condensation resistant surface. Parylenehas very low vapor pressure, 10 to −9, which allows it to be used inmultiple environments and climates—even including a space environment(e.g., components in space shuttles, etc.). In certain aspects, theoutermost protective transparent layer is applied as a surface coatingfor cold climate Low-e windows and includes high transparency from 380nm to 12 microns heat region, sensor region (3-5 microns) opticalwindow/viewport surface protection, and protection of thermal regionequipment windows (8 to 12 microns).

In certain aspects, the transparent article has an electrical sheetresistance ranging from 1 to 120 Ohm/sq. In certain aspects the articlehas an electrical sheet resistance ranging from 1 to 20 Ohm/sq for RFshielding transparent windows, 2 to 50 Ohm/sq, for Low-e windows, or 2to 50 Ohm/sq. for transparent electrodes.

In certain aspects, the article is an electrode adapted for use in anoptoelectrical devices, such as electrochromic windows/displays, liquidcrystals devices/displays, light emitting diodes (LED, OLED), electrodefor solar cells.

In certain aspects, the article is adapted for adhering to a glasswindow and/or for retrofitting onto a glass window. In this aspect, thetransparent article exhibits electromagnetic interference (EMI)shielding properties. EMI shielding of transparent windows is importantfor displays, infrared cameras and electronic communication privacyrooms. For example, the transparent articles may achieve a shieldingattenuation of −45 dB for ˜1 Ohm/sq sheet resistance and visibletransparency of 45% with shielding at a frequency of 10 GHz to 100 GHz.2.6 Ohm/sq 81% transparent coating system deposited on PET substratethat reaches −35 dB shielding efficiency from 10 GHz to 100 GHz region.

Also disclosed herein are methods of preparing the above mentionedtransparent article(s). The methods include (a) providing a substrateadapted to carry a transparent and electrically conductive thin filmthereon, the thin film including an optical matching, adhesionpromoting, stress releasing layer, a first antireflection layer, a metallayer adapted for infra-red reflection and electrical conductivity, asecond antireflection layer, and an optional transparent outermostprotective transparent layer; (b) depositing the optical matching stressreleasing layer directly on the substrate at a thickness ranging from1000 Å to 10,000 Å; (c) depositing the first antireflection layerdirectly on the optical matching, adhesion promoting, stress releasinglayer at a thickness ranging from 100 Å to 1000 Å; (d) depositing themetal layer adapted for infra-red reflection and electrical conductivitydirectly deposited on the first antireflection layer at a thicknessranging from 50 Å to 400 Å; (e) depositing the second antireflectionlayer directly on the metal layer adapted for infra-red reflection at athickness ranging from 100 Å to 1000 Å thereby forming the transparentarticle, and (f) optionally depositing an outermost protectivetransparent layer on the second antireflection layer at a thicknessranging from 100 Å to 10,000 Å, wherein: no buffer layer is positionedbetween the metal layer adapted for infra-red reflection and electricalconductivity and the second antireflection layer, and the transparentand electrically conductive thin film maintains, without loss, opticaland electrical properties for up to nine years when stored at ambienthumidity and/or room temperature. In certain aspects, the method furtherincludes depositing a third antireflection layer directly on the secondantireflection layer at a thickness ranging from 100 Å to 1000 Å, thethird antireflection layer made from the same material and havingsubstantially the same thickness as the first antireflection layer;depositing a second metal layer adapted for infra-red reflection andelectrical conductivity directly on the third antireflection layer at athickness ranging from 50 Å to 400 Å; and depositing a fourthantireflection layer directly on the second metal layer adapted forinfra-red reflection at a thickness ranging from 100 Å to 1000 Å, thefourth antireflection layer made from the same material and havingsubstantially the same thickness as the second antireflection layer—withthe proviso that no buffer layer is deposited between the second metallayer and fourth antireflection layer. In certain aspects, an outermostprotective transparent layer is directly deposited on the fourthantireflection layer at a thickness ranging from 100 Å to 10,000 Å.

In certain aspects, step (e) includes depositing a second metal layer onthe metal layer of step (d) and subsequently oxidizing the second metallayer thereby forming the second antireflection layer including a metaloxide therein.

In certain aspects, the articles made with the above disclosed methodshave an optical transparency of at least 30% between a wavelengthranging from 380 nm to 780 nm and has at least 30% heat rejection at awavelength ranging from 380 nm to 2200 nm. In certain aspects, anoptical transparency of at least 40%, at least 50% or at least 60%between a wavelength ranging from 380 nm to 780 nm and has at least 40%,at least 50%, or at least 60% of total solar reflectance of heatrejection at a wavelength ranging from 380 nm to 2200 nm. In certainaspects, the articles made with the above disclosed methods have 85% to98% coated-surface-reflection around the heat region ranging from 8-12microns.

Additional features, aspects and advantages of the invention will be setforth in the detailed description which follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the invention as described herein. It is to beunderstood that both the foregoing general description and the followingdetailed description present various embodiments of the invention, andare intended to provide an overview or framework for understanding thenature and character of the invention as it is claimed. The accompanyingdrawings are included to provide a further understanding of theinvention, and are incorporated in and constitute a part of thisspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention are better understood when the following detailed descriptionof the invention is read with reference to the accompanying drawings, inwhich:

FIGS. 1A and 1B depict transparent articles according to the prior arthaving a buffer layer(s) deposited directly between its metal andantireflection layers;

FIGS. 2A, 2B, 2C, and 2D depict first, second, third, and fourthembodiments of the transparent articles disclosed herein with eacharticle omitting a buffer layer between the first metal and secondantireflection layers, and when present, omitting a buffer layer betweenthe second metal and fourth antireflection layers;

FIGS. 3A and 3B depict a fifth and sixth embodiment of the transparentarticles that correspond to the first and second embodiments in FIGS. 2Aand 2B with each respectively further including an outer protectivetransparent layer;

FIG. 4 schematically depicts steps in the method of making thetransparent articles disclosed herein;

FIG. 5A schematically depicts the functionality of an insulated glassunit (IGU) according to one embodiment having the disclosed transparentarticles positioned between internal surfaces of two glass panes (glasswindow) and contacted with visible light and infrared wavelengths; FIG.5B schematically depicts the functionality of another embodiment where atransparent article is attached to a single glass pane (glass window)and contacted with visible light and infrared wavelengths; FIG. 5Cschematically depicts a second insulated glass unit (IGU) having twotransparent articles positioned between internal surfaces of two glasspanes (glass windows) in which one transparent article is attached to aglass pane and a second transparent article is suspended between twoconvection spaces of the second IGU; FIG. 5D schematically depictsanother embodiment in which the transparent article is adhered to andretrofitted on an existing glass pane (glass window); FIG. 5Eschematically depicts the RF shielding functionality (also referred toas EMI shielding or EMI shielding properties) of the disclosedtransparent articles for an enclosed room;

FIG. 6 is a graph demonstrating environmental stability and durabilityof the disclosed transparent articles (i) immediately after making thearticle(s), (ii) after aging the article(s) for 6 years, and (iii) afteraging the article(s) for 8.5 years respectively at ambient humidity androom temperature;

FIG. 7A is a graph depicting the heat region transparency of theprotective coating (i) including a control expressed as 100% reflectancein the Figure legend and (ii) FTIR reflectance spectra for thin filmsdisclosed herein deposited on a Melinex® substrate (polyester substrate)that either include or omit the outermost protective transparent layerin the 0.38 μm to 25.0 μm region; FIG. 7B is a graph depicting thevisible and solar region transparency of outermost transparent coatingdeposited on glass in the 0.38 μm to 25.0 μm region; FIG. 7C is a graphdepicting the visible transmittance spectra of the transparent articlesdisclosed herein that are deposited on a Melinex® substrate or omit theoutermost protective transparent layer in the 0.38 μm to 25.0 μm region;

FIG. 8A is a graph depicting visible transmittance spectra oftransparent articles that either include or omit the outermostprotective transparent layer, and FIG. 8B is a graph depicting visibletransmittance in the heat region Reflectance spectra of transparentarticles of the samples from FIG. 8A that either include or omit theoutermost protective transparent layer;

FIG. 9A is a graph depicting visible transmittance spectra for thinfilms disclosed herein deposited on a Melinex® substrate (polyestersubstrate) that either include) or omit the outermost protectivetransparent layer; FIG. 9B is a graph depicting Reflectance spectra forthin films (as disclosed in FIG. 9A) deposited on a Melinex® substrate(polyester substrate) that either include or omit the outermostprotective transparent layer; FIG. 9C depicts an extended heat regionand FTIR reflectance graphs of the transparent articles, which arefurther detailed in Example 2, coated with 1500 Å, 2500 Å, and 5000 Åprotective transparent coatings respectively; and

FIG. 10 provides a schematic depiction of an electrochromic device usedto study transmission with the exemplary articles and thin filmsdisclosed herein.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter withreference to the accompanying drawings in which exemplary embodiments ofthe invention are shown. However, the invention may be embodied in manydifferent forms and should not be construed as limited to therepresentative embodiments set forth herein. The exemplary embodimentsare provided so that this disclosure will be both thorough and complete,and will fully convey the scope of the invention and enable one ofordinary skill in the art to make, use and practice the invention. Likereference numbers refer to like elements throughout the variousdrawings.

FIGS. 2A-3B depict various transparent articles 100, 200, 101, 201, 300,400 disclosed herein, and FIG. 4 further schematically depicts the stepsfor making the transparent articles disclosed herein. These transparentarticles preferably exhibit anti-solar, low emissivity, electricallyconductive properties, and/or electromagnetic shielding properties andcan be preferably stored indefinitely while concurrently maintaininghigh environmental stability and durability for years without needing tobe immediately laminated and/or assembled into a multi-pane windows(e.g., FIGS. 5A and 5C), thus avoiding degradation issues exhibited byconventional thin film coating systems. The transparent articlesdisclosed herein can be formed on transparent flexible, rigid flat,textured surfaces, or fabrics (collectively referred to as substrate 20)as further disclosed herein.

FIGS. 2A and 2B depict a first embodiment 100 and a second embodiment200 of the disclosed transparent articles, and FIGS. 2C and 2D disclosea third embodiment 101 and a fourth embodiment 201 respectively. Each ofthese embodiments utilize a substrate 20, a first antireflection layer140, a first metal layer 150, and a second antireflection layer 160,wherein no buffer layer (e.g., a buffer layer comprising Ni, Cr, Ti, Si,Ni—Cr, and/or oxides thereof) is deposited between the first metal layer150 and the second antireflection layer 160. As shown in FIGS. 2B and 2Dwhen compared with FIGS. 2A and 2C, in certain aspects the opticalmatching/adhesion layer 130 may be omitted from the transparent articlesdepending on the selected substrate 20. As further shown in FIGS. 2C and2D and when compared to FIGS. 2A and 2B, in certain aspects a thirdantireflection layer 140, a second metal layer 150, and a fourthantireflection layer 160 may be deposited in the transparent articles101, 201 that also omit a buffer layer (e.g., a buffer layer comprisingNi, Cr, Ti, Si, Ni—Cr, and/or oxides thereof) deposited between thesecond metal layer and fourth antireflection layer when a second metallayer and fourth antireflection layer are present in the articles. Whenthe third antireflection layer is present, the overall thickness of thesecond and third antireflection layers (combined) are approximatelydouble the total thickness of the first antireflection layer. Theembodiments shown in FIGS. 2C and 2D are generally referred to as doublelow-e articles. Specifically, the transparent articles disclosed inFIGS. 2A-2D include a substrate 20 adapted for carrying a transparentand electrically conductive thin film thereon, the thin film including,in certain embodiments, an optical matching stress releasing layer 130,a first antireflection layer 140, a first metal layer 150 adapted forinfra-red reflection and electrical conductivity, and a secondantireflection layer 160.

In certain aspects and as shown in FIGS. 2A, 2C, and 4, the opticalmatching stress releasing layer 130 (when present) is directly depositedon the substrate 20 at a thickness ranging from 1000 Å to 10,000 Å. Incertain instances and in order to eliminate reflectance and/or surfacetension between the substrate-thin film interface, the optical matchingstress releasing layer 130 (also referred herein as “optical matching,adhesion promoting, stress releasing layer”) may be present. Whenpresent, the optical-matching, adhesion promoting, stress releasinglayer material selected depends on the substrate utilized. Forapplications in the visible portion of the spectrum (e.g., displays,window panes, etc.) the substrate may be a glass, such as a borosilicateglass, or a plastic, such as polyethyleneterephtalate (PET), polyimide,or any other transparent plastic. For applications in the infra-redportion of the spectrum the substrate may be made of many suitablematerials known to be transparent in the spectral region of interest.Materials of this sort include, but are not limited to, silicon,germanium, zinc sulfide, and zinc selenide.

For the articles disclosed herein, the optical matching stress releasinglayer 130 is generally a silicon-containing film (e.g., a silicondioxide film) having a thickness ranging from 1000 Å to 10,000 Å, with apreferred thickness ranging from 3000 Å to 7000 Å for both visible andIR transparent conditions. In order to eliminate reflectance andcontamination, from the substrate-thin film interface, and stresscreated by the deposited film a graded density coating or a matchingcoating system is employed in preferred embodiments. Thus, in someembodiments, e.g. where silicon is used as the substrate, the opticalmatching stress releasing layer 130 is a graded silicon-oxygen film inwhich the silicon to oxygen composition ratio the metallic conductionfilm (first metal layer 150 and/or second metal layer 150).

As shown in FIGS. 2A-3B and as further detailed in FIG. 4, a firstantireflection layer 140 is directly deposited either on the substrate20 or on the optical matching stress releasing layer 130 at a thicknessranging from 100 Å to 1000 Å and more preferably ranges from 200 Å to600 Å. The first antireflection layers 140 include at least one of W oroxides thereof (e.g., WO₃), Sn or oxides thereof (e.g., SnO₂), Zn oroxides thereof (e.g., ZnO), Ti or oxides (e.g., TiO2) or nitridesthereof, Al or oxides thereof, Ta or oxides thereof (e.g., Ta₂O₅), Hf oroxides thereof, Nb or oxides thereof, an indium tin oxide (ITO), Bi oroxides thereof (e.g., Bi₂O₃), Ce or oxides thereof, Pr or oxidesthereof, Ni or oxides thereof, aluminum doped zinc oxide (AZO), orindium zinc oxide (IZO). In certain preferred aspects, the firstantireflection layer 140 of the article is WO₃.

As further shown in FIGS. 2A-3B and as also detailed in FIG. 4 a firstmetal layer 150 adapted for infra-red reflection and electricallyconductive film is directly deposited on the first antireflection layer140 at a thickness ranging from 50 Å to 400 Å and more preferably rangesfrom 70 Å to 300 Å. The first metal layer 150 includes at least one ofAg, Au, Ag—Au, Cu, Al, Pd, Pt, Ni, Rd, or Zn. In certain preferredaspects, the first metal layer 150 is Ag.

As further shown in FIGS. 2A-3B and as further detailed in FIG. 4, thesecond antireflection layer 160 is directly deposited on the metal layeradapted for infra-red reflection at a thickness ranging from 100 Å to1000 Å and more preferably ranges from 200 Å to 600 Å. The secondantireflection layer 160 includes at least one of W or oxides thereof(e.g., WO₃), Sn or oxides thereof (e.g., SnO₂), Zn or oxides thereof(e.g., ZnO), Ti or oxides (e.g., TiO2) or nitrides thereof, Al or oxidesthereof, Ta or oxides thereof (e.g., Ta₂O₅), Hf or oxides thereof, Nb oroxides thereof, an indium tin oxide (ITO), Bi or oxides thereof (e.g.,Bi₂O₃), Ce or oxides thereof, Pr or oxides thereof, Ni or oxidesthereof, aluminum doped zinc oxide (AZO), or indium zinc oxide (IZO). Incertain preferred aspects, the second antireflection layer 160 of thearticle is W and/or WO₃. In certain preferred aspects, the secondantireflection layer 160 of the article is WO₃.

In certain aspects and when the first and/or second metal layers 150 aresilver (Ag) in the disclosed transparent articles, the metal surface todielectric layer (antireflection layer) contact interface is veryimportant because if electron scattering is lost and/or reduced at themetal surface/dielectric layer interface undesirable, extra interfaceresistance results, which renders the transparent articles considerablyless effective for their desired purposes. In certain preferred aspectsand when the first and/or second metal layers 150 are silver (Ag) in thedisclosed transparent articles, W and/or WO₃ makes excellent, smoothcontact with the silver layer, which provides long term environmentaland thermal stability/longevity of the transparent articles whileconcurrently avoiding the undesirable effects (e.g., extra interfaceresistance, decreased electron scattering etc.) discussed above. Tofurther evidence this fact, FIG. 6 shows long term environmentalstability of the exemplary transparent articles disclosed herein. Inthese aspects, WO₃ is particularly preferred because of its highrefractive index. For example, in the visible region, its refractiveindex is 2.2, which allows for very thin layers to be deposited thatstill provide for antireflection. Furthermore W and WO₃ have highsputtering rates, and can be advantageously deposited on the puremetallic target/metal layer (e.g., a silver (Ag) layer) with little orno metal target erosion thereby quickly and efficiently forming a harddurable coating over the metal layer and further forming a hard, durabletransparent article. For the transparent articles disclosed herein, Wand WO₃ are also particularly preferred for the transparent articlesdisclosed herein for at least the advantages discussed above especiallywhen compared with other common oxides used as antireflection coating(s)(also referred to as “AR coating(s)”) in Low-e systems, For example,when ZnO is used as an antireflection layer, ZnO has a yellow residualcolor formed soft films, effected by UV radiation(s) and can furtherexhibit arching problems.

As shown in Table 1 below, the presence of W and/or WO₃ (as anantireflection layer) in the transparent article(s) is dependent on thedeposition process utilized to produce the transparent article. The twodifferent deposition processes used in Table 1 are e-beam deposition andsputtering deposition. With regard to e-beam deposition, e-Beamdeposition is a thermal evaporation process that heats a source materialby a focused e-beam and evaporates the source material from a solidphase to gas phase (gas form) wherein the gas form of source materialcondenses on the substrate surface or another previously deposited layerthereby forming a thin film layer of source material. One skilled in theart understands that e-beam deposition is how one deposits an oxidelayer from an oxide source. In certain aspects and for Reactiveevaporation one can use metal source (e.g., W) and evaporate the metalsource (e.g., W) in a reactive gas environment, e.g., oxygen environmentand the resulting film will be oxide of source material (e.g., WO₃formed from deposited W that is subsequently oxidized in the reactivegas environment). For example, if e-beam deposition is utilized whendepositing the second antireflection layer, then the secondantireflection layer may be exclusively WO₃. In the sputteringdeposition either DC or RF sputtering a metal target, for example ametal target of the antireflection layer such as W, is used as a sourcematerial. In a vacuum environment and the metal surface of the metaltarget, for example a metal target of the antireflection layer such asW, is bombarded by an Ar-reactive gas mixture (Oxygen for oxides). Arsputters metal particles from target surface and oxygen reacts with themetal to form a metal oxide film (e.g., WO₃ formed from deposited W thatis subsequently oxidized in the reactive gas environment as shown inTable 1) deposited over, for example, the metal layer(s) 150 discloseherein. However, if sputter deposition is utilized to deposit the secondantireflection layers, desired antireflective material (e.g., W, Sn, Zn,Ti, Al, Ta, Hf, Nb, Bi, Ce, Pr, Ni) may be first deposited over themetal layer 140, and post-deposition, the desired antireflectivematerial may be treated (e.g., introducing Ar/O₂ mixture into thechamber thereby oxidizing and transforming the desired antireflectivemetal from an outermost surface inwardly towards the first metal layer140 thereby forming the second antireflection layer without oxidizingthe first metal layer 140. For example, in view of FIGS. 2A-3B and FIG.4, W may be first deposited over the first metal layer 140, andpost-deposition of W, oxygen (O₂) may be introduced into the chamberthereby oxidizing the second metal layer to form the secondantireflection layer 160 without oxidizing the first metal layer.

As further shown in FIGS. 2A-3B, no buffer layer comprising Ni, Cr, Ti,Si, Ni—Cr, and/or oxides thereof is deposited between the first metallayer 150 and the second antireflection layer 160. By omitting thebuffer layer (buffer layer comprising Ni, Cr, Ti, Si, Ni—Cr, and/oroxides thereof), the transparent articles disclosed hereinadvantageously achieves very long shelf life (FIG. 6) and environmentaland temperature stability/durability when compared to all othercurrently known silver based low-e coatings that have buffer layers(buffer layer comprising Ni, Cr, Ti, Si, Ni—Cr, and/or oxides thereof)between metal and antireflective layers.

In certain aspects, the articles 100, 200 depicted in FIG. 2A and FIG.2B may have an outermost protective transparent layer 170 deposited onthe second antireflection layer 160 at a thickness ranging from 100 Å to10,000 Å and more preferably from 600 Å to 10,000 Å. For example, thearticles 100, 200 depicted in FIG. 2A and FIG. 2B correspond to articles300, 400 depicted in FIGS. 3A and 3B, which have an outermost protectivetransparent layer 170. When the outermost protective transparent layeris present in the article(s), the outermost protective transparent layermay include/be formed from a poly(p-xylylene) outer coating (e.g.,parylene C). In certain aspects, the outermost protective transparentlayer 170 does not affect reflectance, transmissivity, and/or lowemissivity of the transparent articles but merely serves as a protectivecoating to further enhance durability of the disclosed articles asshown, for example, in FIG. 6, which demonstrate environmental stabilityand durability of the disclosed transparent articles (i) immediatelyafter making the article(s), (ii) after aging the article(s) for 6years, and (iii) after aging the article(s) for 8.5 years respectivelyat ambient humidity and room temperature.

In view of FIG. 5B and when the transparent article is applied to, forexample, a glass window (or window pane), the outer protective layer mayfurther protect the second antireflection layer from smudging (e.g.,from residual oils left on the article surface) when contacted withhuman skin. For example, if no outer protective layer were included onthe transparent article shown in FIG. 5B and the article wassubsequently contacted with human skin, irremovable smudging couldresult, which would eventually degrade the outermost antireflectionlayer 160 (e.g., second antireflection layer or fourth antireflectionlayer) that is not coated with the outer protective transparent layer170. In certain preferred aspects, the outer protective transparentlayer 170 is a washable and blow dryable, water repellant, hydrophobic,and chemically resistant coating that can withstand nearly all cleaningsolutions. Regarding the outer protective transparent layer 170, FIG. 7Afurther shows heat region infrared reflectance of an exemplarytransparent article with and without the outer transparent protectivelayer 170. As shown in FIG. 7A, both the transparent article includingand omitting the outer transparent protective layer have nearly the samereflectance value indicating that outer protective layer 170advantageously has nearly no absorption in this spectral region. FIG. 7Bfurther shows that the outer protective transparent layer 170 istransparent in the visible region, and more specifically shows spectraltransmittance of a glass substrate with and without the outertransparent protective layer 170. Thus, because the outer protectivelayer protects underlying layers (e.g., antireflection and metal layers)and has little effect on reflectance and transmittance when compared toidentical articles that omit this protective layer, including the outerprotective layer is beneficial in certain transparent articleembodiments.

In certain aspects and as further shown in FIGS. 2C, 2D, and 4,transparent articles 101, 201 having double low-emissivity thin filmsmay also be desired. Low-e coating(s) are specialtransmission-reflection filters having high visible transmission,especially when coated on glass window(s), and high reflection/rejectionin the infrared region. In order to enhance/improve low-e performance,another Low-e may be added, which are called double Low-e, or superLow-e. For example and as shown in FIG. 4 double low-emissivity thinfilms may be formed by providing the articles 100, 200 shown, forexample, in FIGS. 2A and 2B and then repeating steps S3-S5 of FIG. 4 toform the third antireflection layer, second metal layer, and fourthantireflection layer. The third antireflection layer substantiallycorresponds in thickness to the first antireflection layer 140 and ispreferably made from the same material (e.g., at least one of W oroxides thereof (e.g., WO₃), Sn or oxides thereof (e.g., SnO₂), Zn oroxides thereof (e.g., ZnO), Ti or oxides (e.g., TiO2) or nitridesthereof, Al or oxides thereof, Ta or oxides thereof (e.g., Ta₂O₅), Hf oroxides thereof, Nb or oxides thereof, an indium tin oxide (ITO), Bi oroxides thereof (e.g., Bi₂O₃), Ce or oxides thereof, Pr or oxidesthereof, Ni or oxides thereof, aluminum doped zinc oxide (AZO), orindium zinc oxide (IZO)) as the first antireflection layer 140. Similarto the articles 100, 200 shown in FIGS. 2A and 2B, the articles 101, 201having double low-emissivity thin films have a second metal layerdeposited directly over the third antireflection layer. The second metallayer substantially corresponds in thickness to the first metal layerand is preferably made from the same material as the first metal layer150 (e.g., at least one of Ag, Au, Ag—Au, Cu, Al, Pd, Pt, Ni, Rd, orZn). As further shown in FIGS. 2C and 2D, a fourth antireflection layeris directly deposited over the second metal layer. The fourthantireflection layer substantially corresponds in thickness to thesecond antireflection layer 160 and is preferably made from the samematerial (e.g., at least one of W or oxides thereof (e.g., WO₃), Sn oroxides thereof (e.g., SnO₂), Zn or oxides thereof (e.g., ZnO), Ti oroxides (e.g., TiO2) or nitrides thereof, Al or oxides thereof, Ta oroxides thereof (e.g., Ta₂O₅), Hf or oxides thereof, Nb or oxidesthereof, an indium tin oxide (ITO), Bi or oxides thereof (e.g., Bi₂O₃),Ce or oxides thereof, Pr or oxides thereof, Ni or oxides thereof,aluminum doped zinc oxide (AZO), or indium zinc oxide (IZO)) as thesecond antireflection layer. Although not depicted in the Figures, thetransparent articles 101, 201 having double low-emissivity may furtherinclude an outermost protective transparent layer 170 havingsubstantially the same thickness and being made from substantially thesame material as the outermost protective transparent layer 170 depictedin FIGS. 3A and 3B.

The transparent articles and thin films disclosed herein preferablyexhibit the highest possible transparency (similar to no coating/filmbeing deposited on the substrate) while concurrently exhibiting thelowest possible sheet resistance/highest possible conductivity, whichdirectly affect heat rejection capability and shielding efficiency asshown, for example, in FIGS. 5A, 5B, and 5E. In certain aspects, thetransparent articles 100, 200, 101, 201, 300, 400 made with the abovedisclosed methods have an optical transparency of at least 30% between awavelength ranging from 380 nm to 780 nm and has at least 30% heatrejection at a wavelength ranging from 380 nm to 2200 nm. In certainaspects, an optical transparency of at least 40%, at least 50% or atleast 60% between a wavelength ranging from 380 nm to 780 nm and has atleast 40%, at least 50%, or at least 60% of total solar reflectance ofheat rejection at a wavelength ranging from 380 nm to 2200 nm.

In certain aspects, each disclosed transparent article 100, 200, 101,201, 300, 400 further exhibits electromagnetic interference shieldingproperties. For example, FIG. 5E schematically a glass window 301 havingat least one transparent article (100, 101, 200, 201) attachedthereto/positioned thereon. The glass window 301 of FIG. 5E is an outersurface of an enclosed room 305 and is adapted to pass visible lightfrom outside to inside the enclosed room while concurrently shieldingRF. In certain aspects, film/transparent article is positioned betweenthe glass 301 and substrate 20, with the substrate 20 being the innermost surface relative to the interior of the enclosed room 305.Specifically, FIG. 5E depicts RF (radio frequency) shieldingfunctionality (also referred to as EMI shielding or EMI shieldingproperties) of the disclosed transparent articles for an enclosed room,and Table 2 below further shows shielding efficiency (“SE”) forexemplary samples of the transparent articles disclosed herein. Inpreferred aspects, the transparent articles achieve a shieldingattenuation of from −10 dB to −45 dB at a frequency of 1 GHz to 100 GHz.Thus, in view of these electromagnetic interference shielding propertiesand when applied to for example a glass window as shown in FIGS. 5A-5E,the transparent article(s) may act as an electromagnetic shield asspecific frequencies.

In certain aspects, the article has an electrical sheet resistanceranging from 1 to 120 Ohm/sq. In certain aspects the article has anelectrical sheet resistance ranging from 1 to 80 Ohm/sq, 1 to 50 Ohm/sq,or 4 to 25 Ohm/sq depending on the application of the coated transparentarticles. For example, in certain aspects the article has an electricalsheet resistance ranging from 1 to 20 Ohm/sq for RF shieldingtransparent windows, 2 to 50 Ohm/sq, for Low-e windows, or 2 to 50Ohm/sq. for transparent electrodes

In certain aspects, each layer (optical matching layer if present, eachantireflection layer, each metal layer(s), and outermost protectivetransparent layer if present) is deposited uniformly throughout thedisclosed transparent articles thereby achieving uniform reflectance,transmissivity, low emissivity, and/or durability throughout the entirearticle.

Various embodiments of the invention may have optical visibleapplications including, for example: low-e films for heat wave rejection(FIGS. 2A, 2B, 3A, 3B), double low-e films for heat wave rejection(FIGS. 2C and 2D), insulated glass units (e.g., FIGS. 5A and 5C),electrodes for displays (FIG. 10), and optical IR applications, and isalso applicable to electrical applications, including electric fieldapplications, such as to displays and electron interaction, for example,with regard to electro-chromic devices and photovoltaics, andtransparent electronics. The invention provides a flexible transparentconductor for displays, for example, or a heat mirror type plasticinsert or direct deposit on glass for windows in architectural orautomotive applications. The invention can also comprise a transparentelectrode for IR devices, and may be used in solar panels, spacecraft orsatellite thermal control variable emittance systems, and on spacecraftsurfaces as a protective coating for electrical charging. In view of theabove generally disclosed applications and as shown in FIG. 5B, thetransparent article(s) in certain aspects is adapted for adhering to aglass window and/or for retrofitting onto a glass window. As alludedabove, these articles preferably exhibit anti-solar, low emissivity,electrically conductive properties, and/or electromagnetic shieldingproperties. For example, FIG. 5B shows an exemplary article adhered to aglass window and having high transmissivity of sunlight from outdoorswhile concurrently trapping/maintaining heat (e.g., infrared) inside.FIGS. 5A, 5C, and 5D further depict variations of the basic conceptshown in FIG. 5B. For example, FIG. 5A depicts the functionality of aninsulated glass unit (IGU) according to one embodiment having thedisclosed transparent articles (200, 201 as shown but may also include100 or 101) positioned between internal surfaces of two glass panes 301(glass window) and a convection space 302 being contacted with visiblelight and infrared wavelengths. FIG. 5C depicts a second insulated glassunit (IGU) having two transparent articles (e.g., any combination of100, 101, 200, 201) positioned between internal surfaces of two glasspanes 301 (glass windows) in which one transparent article is attachedto a glass pane and a second transparent article is suspended betweentwo convection spaces 302 of the second IGU. FIG. 5D depicts anotherembodiment in which the transparent article (100, 200) is adhered withan adhesive to/retrofitted on an existing glass pane 301 (glass window),and as further shown, the embodiment of FIG. 5D may further include atransparent insulator 304. In certain aspects and as further shown inFIG. 5E, the transparent articles exhibit electromagnetic interferenceshielding properties that act as an electromagnetic shield as specificfrequencies. In certain aspects and as further shown in FIG. 10, thearticles disclosed herein 501 a, 501 b (which each independently includeone of 100, 101, 200, 201, 300, 400) may be included in anelectrochromic device 500. Those skilled in the art will appreciate thatmany other applications of the invention are possible.

It should be further noted that FIG. 7C is a graph depicting the visibletransmittance spectra of the transparent articles disclosed herein thatare deposited on a Melinex® substrate (polyester substrate) that eitherinclude (defined as “PAR. on Melinex” in this Figure) or omit (definedas “Melinex” in this Figure) the outermost protective transparent layerin the 0.38 μm to 25.0 μm region.

It should be further noted that FIG. 8A is a graph depicting visibletransmittance spectra of transparent articles that either include oromit the outermost protective transparent layer, and FIG. 8B is a graphdepicting visible transmittance in the heat region Reflectance spectraof transparent articles that either include or omit the outermostprotective transparent layer.

It should be further noted that FIGS. 9A and 9B depicts visibletransmittance spectra and reflectance or a thin films disclosed hereindeposited on a Melinex® substrate (polyester substrate) that eitherinclude or omit the outermost protective transparent layer.

Those skilled in the art will also appreciate that many other processes,such as the use of a resistively heated source, or sputtering, could beused for the deposition. Moreover, different choices of the backgroundpressure, substrate-to-source distance, deposition rate, and substratetemperature could be used. Inasmuch as the morphology of very thin filmsof the sort used in the present invention are dependent on depositionconditions, those skilled in the thin film arts will also appreciatethat different deposition processes could be used to form multilayerfilms equivalent to those herein described, but that demonstrate thedesired optical and electronic properties at somewhat different nominalvalues of film thickness.

Prior to making optical and electrical measurements on the depositedfilms described in the following examples, the adherence of each film toits substrate was assessed by a conventional cellophane tape strippingtest. In all cases reported in the following examples the tape testshowed excellent adhesion.

WORKING EXAMPLES

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how thecompounds, compositions, and methods described and claimed herein aremade and evaluated, and are intended to be purely exemplary and are notintended to limit the scope of what the inventors regard as theirinvention. Efforts have been made to ensure accuracy with respect tonumbers (e.g., amounts, temperature, etc.) but some errors anddeviations should be accounted for. Unless indicated otherwise, partsare parts by weight, temperature is in ° C. or is at ambienttemperature, and pressure is at or near atmospheric.

Table 1 below depicts various articles envisioned to be made from theprocess and materials disclosed herein.

TABLE 1 Optical First Matching/ Antireflection Second Stress Layer(Metal Metal Antireflection Deposition Releasing Oxide Layer) LayerMetal Oxide (WO₃) Type Substrate Layer (SiO₂) (WO₃) (Ag) Layer Metal (W)E-Beam Glass No Yes Yes NA Yes Deposition Polymer Yes Yes Yes NA Yes(Polycarbonate) Polyethylene Yes Yes Yes NA Yes Terephthalate TypeFabric Type Yes Yes Yes Yes Sputter Glass No Yes Yes Yes Yes DepositionPolymer Yes Yes Yes Yes Yes (Polycarbonate) Polyethylene Yes Yes Yes YesYes Terephthalate Type Fabric Type Yes Yes Yes Yes Yes

Method of Making Transparent Articles:

Examples 1-4 are discussed further below including methods of making thetransparent articles of Examples 1-3 and the properties exhibited byExamples 1-3 are further shown in Table 2 below. Generally, the exampleswere made by using multiple vacuum coaters having different depositionprocesses and vacuum conditions e.g., e-beam and sputtering processesfor thin film of all inorganic coating materials and thermal chemicalvapor deposition, thermal-CVD, for Parylene C films.

Prior to deposition each substrate was plasma cleaned in a vacuum byexposing the substrate to 30 sec to 2 min Ar bombardment. Next, eachsubstrate of Examples 1-3 (as discussed further below and as furthershown in Table 2) were deposited and formed by (i) e-beam directeddeposition and (ii) a sputtering process.

For e-beam deposition, the oxide starting material (e.g., SiO₂ (opticalmatching, adhesion promoting, stress releasing layer), WO₃ (firstantireflection layer), Ag (metal layer), and WO₃ (second antireflectionlayer)) was loaded in crucibles as well as the clean substrates werelocated in the deposition chamber, the chamber door was closed thansystem pump down to 10⁻⁶ Torr background pressure and e-beam wasdirected to crucibles subsequently deposited at rates of ranging from 2to 30 Å/sec thereby forming Examples 1-3.

For the sputtering process a multi-region deposition environment wasused e.g., a reactive sputtering technique from metallic targets of Wwere applied to deposit antireflective oxide coatings of WO₃ films usingAr-oxygen mixture of 1 to 10 10⁻⁴ Torr (background pressure 10⁻⁵ Torr)of vacuum level and sputtering power was 0.2 to 5 Watts/cm², anddeposition rates ranged from 1 to 10 Å/sec. SiO₂ was deposited from 5%boron doped Si target using RF reactive sputtering or e-beam process. Agand W metallic films sputtered from pure Ag and W targets using only Aras a sputtering gas.

Example 1 WO₃/Ag/WO₃ Films Formed by Different Deposition Techniques A.A WO₃/Ag/WO₃ Film Formed by E-Beam Deposition

In this example, a clean 2-4 mm glass or 0.1 to 0.125 thick Melinex wasused to deposit (via e-beam deposition) of the WO₃/Ag/WO₃ and/orSiO2/WO₃/Ag/WO₃ films thereon. Layers of a whole coated article withWO₃/Ag/WO₃ and/or SiO2/WO₃/Ag/WO₃ were subsequently deposited on thesubstrate in one pump down cycle; a first antireflection layer, a metallayer, and a second antireflection layer to form the coated articleshown in FIG. 2B and FIG. 2A respectively. First, vacuum system pumpeddown to 10⁻⁶ Torr background pressure and WO₃ loaded crucible heated bye-beam subsequently deposited at a rates of 3 Å/sec thereby forming thefirst antireflection layer of WO₃ at a thickness of 320 Å. Next, Ag wasdeposited from Ag loaded crucibles were subsequently uniformly depositedin 10⁻⁶ Torr background pressure over the first antireflection layer ata rates of 2 Å/sec thereby forming the Ag metal layer at a thickness of90 Å. Next, WO₃ loaded crucible was heated by e-beam when vacuum levelwas reached to 10⁻⁶ Torr and a WO3 film subsequently uniformly depositedover the Ag metal layer at a rates of 3 Å/sec thereby forming the secondantireflection layer of WO₃ at a thickness of 330 Å, thereby forming thetransparent article of FIG. 2B having the properties further shown inTable 2 below and FIG. 6.

B. A SiO₂/WO₃/Ag/WO₃ Film Formed By Sputter Deposition

In this example, a clean 2-4 mm glass or 0.1 to 0.125 mm thick Melinexsubstrate was used to deposit the transparent article. First, cleanedglass or Melinex substrate was introduced to the coating system bypassing through a multi station sputter deposition chamber of modifiedDenton 40 coater. In the sputtering process a multi-region depositionenvironment were used e.g., reactive sputtering technique from metallictargets; sputtering gas Argon and reactive gas oxygen or nitrogen wasused. For metal deposition only a sputtering gas (Argon) was used.

In general, 1 to 10 10⁻⁴ Torr (background pressure 10⁻⁵ Torr) of vacuumlevel was used and sputtering power was 0.2 to 5 Watts/cm², anddeposition rates ranging from 1 to 10 Å/sec for materials ofSiO₂/WO₃/Ag/WO₃ coating system. Where SiO₂ films were used for adhesionenhancing performance required on polymer substrates and was depositedfrom 5% boron doped Si target using RF reactive sputtering. Ag filmssputtered from pure Ag target using only Ar as a sputtering gas.

Deposition of First AR film (320 Å thickness WO₃): The glass substratewas moved under W target using a sputtering system pump down to 5×10⁻⁵Torr background pressure and increased to an operating pressure of3×10⁻³ by injecting operating gases. The coating station filled withArgon/Oxygen mixture for WO₃ deposition—where Argon was the sputteringgas and oxygen was reactive gas used to convert W metal to WO₃ therebyforming the first antireflection layer. For this example, the gasmixture is Argon, 45 sccm, and oxygen is 60 sccm. Deposition power was2.2 Watt/cm² and glass moving rate is 2 m/min.

Deposition of Metal layer (90 Å thickness Ag). WO₃ coated glass wasmoved to an Ag target station and the system pumped down to 5×10⁻⁵ Torrbackground pressure and increased to an operating pressure of 2×10⁻³Torr by injecting the operating gas of Argon 50 sccm for metallic Aglayer sputtering, thereby forming the metal layer. Deposition power was1.1 Watt/cm² and glass moving rate is 2 m/min.

Second AR Film (Deposition of W buffer and conversion to WO₃). TheWO₃/Ag coated glass substrate (as described immediately above) wassubsequently moved under a W target with the coating system pump down to5×10⁻⁵ Torr background pressure and then increased to an operatingpressure of 1.1×10⁻³ Torr by injecting the operating gas of 20 sccmArgon. The metallic W layer of 17 Å was deposited using a depositionpower of 0.5 Watt/cm² thereby forming a glass substrate coated withWO₃/Ag/W layers. Next, the glass substrate coated with WO3/Ag/W layerswas positioned under W target system pump down to 5×10⁻⁵ Torr backgroundpressure and then increased to an operating pressure of 3×10⁻³ byinjecting operating gases. The coating station filled with Argon/Oxygenmixture for WO₃ deposition at 330 Å in thickness where Argon was thesputtering gas and oxygen was the reactive gas converting W metal toWO₃. For this example gas mixture was Argon at 45 sccm and oxygen at 65sccm. Deposition power was 2.2 Watt/cm² and glass moving rate is 2m/min.

C. A SiO2/WO₃/Ag/WO₃/WO₃/Ag/WO₃ Film Formed by Sputter Deposition

In this example, a clean 2-4 mm glass substrate was used to deposit thetransparent article. First, cleaned glass was introduced to the coatingsystem by passing through a multi station sputter deposition chamber ofmodified Denton 40 coater. In the sputtering process a multi-regiondeposition environment were used e.g., reactive sputtering techniquefrom metallic targets; sputtering gas Argon and reactive gas oxygen ornitrogen was used. For metal deposition only a sputtering gas (Argon)was used.

In general, 1 to 10 10⁻⁴ Torr (background pressure 10⁻⁵ Torr) of vacuumlevel was used and sputtering power was 0.2 to 5 Watts/cm², anddeposition rates ranging from 1 to 10 Å/sec for materials ofSiO₂/WO₃/Ag/WO₃/WO₃/Ag/WO₃ coating system. Where SiO₂ films were usedfor adhesion enhancing performance required on polymer substrates andwas deposited from 5% boron doped Si target using RF reactivesputtering. Ag films sputtered from pure Ag target using only Ar as asputtering gas.

Deposition of First AR film (320 Å thickness WO₃): The glass substratewas moved under W target using a sputtering system pump down to 5×10⁻⁵Torr background pressure and increased to an operating pressure of3×10⁻³ by injecting operating gases. The coating station filled withArgon/Oxygen mixture for WO₃ deposition—where Argon was the sputteringgas and oxygen was reactive gas used to convert W metal to WO₃ therebyforming the first antireflection layer. For this example, the gasmixture is Argon, 45 sccm, and oxygen is 60 sccm. Deposition power was2.2 Watt/cm² and glass moving rate is 2 m/min.

Deposition of Metal layer (80 Å thickness Ag). WO₃ coated glass wasmoved to an Ag target station and the system pumped down to 5×10⁻⁵ Torrbackground pressure and increased to an operating pressure of 2×10⁻³Torr by injecting the operating gas of Argon 50 sccm for metallic Aglayer sputtering, thereby forming the metal layer. Deposition power was1.1 Watt/cm² and glass moving rate is 2 m/min.

Center AR Film (Deposition of W buffer and conversion to WO₃). TheWO₃/Ag coated glass substrate (as described immediately above) wassubsequently moved under a W target with the coating system pump down to5×10⁻⁵ Torr background pressure and then increased to an operatingpressure of 1.1×10⁻³ Torr by injecting the operating gas of 20 sccmArgon. The metallic W layer of 20 Å was deposited using a depositionpower of 0.5 Watt/cm² thereby forming a glass substrate coated withWO₃/Ag/W layers. Next, the glass substrate coated with WO3/Ag/W layersremained positioned under W target system pump down to 5×10⁻⁵ Torrbackground pressure and then increased to an operating pressure of3×10⁻³ by injecting operating gases. The coating station was filled withArgon/Oxygen mixture where Argon was the sputtering gas and oxygen wasthe reactive gas converting W metal to WO₃ and 650 Å nearly double inthickness WO₃ layer were deposited as a center antireflective layer. Forthis example gas mixture was Argon at 45 sccm and oxygen at 65 sccm.Deposition power was 2.2 Watt/cm² and glass moving rate is 2 m/min.

Deposition of the Second Metal layer (80 Å thickness Ag). TheWO₃/Ag/WO₃/WO₃ coated glass was moved for the second time under Agtarget station and the system pumped down to 5×10⁻⁵ Torr backgroundpressure and increased to an operating pressure of 2×10⁻³ Torr byinjecting the operating gas of Argon 50 sccm for metallic Ag layersputtering, thereby forming the second metal layer (i.e.,SiO₂/WO₃/Ag/WO₃/WO₃/Ag). Deposition power was 1.1 Watt/cm² and glassmoving rate is 2 m/min.

Fourth AR Film (Deposition of W buffer and conversion to WO₃). TheWO₃/Ag/WO₃/WO₃/Ag coated glass substrate was subsequently moved under aW target with the coating system pump down to 5×10⁻⁵ Torr backgroundpressure and then increased to an operating pressure of 1.1×10³ Torr byinjecting the operating gas of 20 sccm Argon. The metallic W layer of 20Å was deposited using a deposition power of 0.5 Watt/cm² thereby forminga glass substrate coated with WO₃/Ag/WO₃/WO₃/Ag/W layers. Next, theglass substrate coated with WO₃/Ag/WO₃/WO₃/Ag/W layers was positionedunder W target system pump down to 5×10⁻⁵ Torr background pressure andthen increased to an operating pressure of 3×10⁻³ by injecting operatinggases. The coating station filled with Argon/Oxygen mixture for WO₃deposition at 330 Å in thickness where Argon was the sputtering gas andoxygen was the reactive gas converting W metal to WO₃ (forming theSiO₂/WO₃/Ag/WO₃/WO₃/Ag/WO₃ coated article). For this example gas mixturewas Argon at 45 sccm and oxygen at 65 sccm. Deposition power was 2.2Watt/cm² and glass moving rate is 2 m/min.

Examples 2 and 3 WO₃/Ag/WO₃ Films Formed On Different Substrates

Examples 2 and 3 provide different formulations of the transparentarticles and further show how layer thicknesses of WO₃ and silver (Ag)effect sample performance. As shown, for example in Table 2 below, athicker silver layer reduces sheet resistance and enhances reflectancein the entire IR region including heat region reflectance of the coatedarticle making the coating better low-e. AR layer thickness controlsoptical performance in the visible region and enhances visibletransmission.

A. Example 2

Example 2 demonstrates the best window coating performance, which ishigh transmission in the visible region, ˜85%, neutral transmission andreflection colors, and emittance of e=0.5 value, which is further shownin Table 2 below. In this example, coatings were deposited on both glassand Melinex substrates by e-beam and sputtering as described above inExample 1.

Substrates in Example 2 were glass and Melinex. Optical matching layerthickness was 4000 Å thick SiO₂, the first AR was 350 Å thick WO₃, themetal layer was 110 Å thick Ag, and the second AR was 350 Å thick WO₃.So, the SiO₂/WO₃/Ag/WO₃ coated transparent article was deposited bye-beam process as described in Example 1A and the SiO₂/WO₃/Ag/W/WO₃transparent article was deposited as described above in Example 1B withan optical matching layer thickness is 4000 Å thick SiO₂, the first ARwas 350 Å thick WO₃, the metal layer was 110 Å thick Ag, 20 Å W, and 350Å thick WO₃.

B. Example 3

Example 3 was the same as Example 2 except where Ag thickness is 175 Åand W buffer thickness is 22 Å for sputter deposition. This example maybe used for a transparent and RF shielding window. The transparentarticle of Example 3 is 75% transparent with shielding efficiency of −42dB. Example 3 is, for example, a sample shown in FIG. 2A and theperformance characteristics are further provided in Table 2 below. Thecoating was deposited on both glass and Melinex substrates. Layerthicknesses of the transparent article are: begin with the desiredsubstrate, deposit the optical matching layer at 4000 Å thickness;deposit the first AR 140 at 380 Å thickness of WO₃, deposit a metallayer at a 175 Å thickness of Ag, deposit second AR 160 at a 380 Åthickness of WO₃. Sputtered equivalents of this example require thickerW buffer of e.g., 18-22 Å.

Table 2 below summarizes performance of Examples 1-3.

TABLE 2 FTIR Reflectance Shielding measured at Efficiency Transmittance¹Sheet 300K; 9.66 μm Emittance (e) SE (dB) T (%) Resistance² λ(μm) = e =Absorption 20 log₁₀ (1 + Examples at5500 Å Rs (Ohm/sq) 2898/T(K)³ e = 1− R (377 Ω/2Rs)) Example 1 90.5 10 0.92 0.08 −25 (dB) (FIG. 6) Example 286 4.1 0.96 0.04 −32 (dB) (FIG. 8A) Example 3 75 1.7 0.98 0.02 −42 (dB)(FIG. 8A) ¹Measured with a Perkin-Elmer Vis-Near IR Spectrometer²Measured with a Four Point Probe ³Wien Displacement Law (D.L. Smith“Thin Film Deposition” McGraw Hill, N.Y. (1995))

Example 4 Depositing the Outer Protective Layer on the TransparentArticle(s)

Parylene N is a poli-para-xylylene and Parylene C produced from the samemonomer modified by the substituting of a chlorine atom for one of thearomatic hydrogen. Parylene films were deposited on the transparentarticles as shown in FIGS. 3A and 3B by using PlasmaTeck Model 5300coating equipment. A thermally heatable crucible was loaded with 2 g per1μ thick of a predefined precursor dimer material and substrates wereloaded for parylene coating. The dimer evaporates under 0.1 Torr vacuumlevel at 150° C. heated crucible. Pyrolysis of the dimer occurs at 680°C. by forming two methylene-methylene bonds to yield para-xylylene thenfilm deposits at 0.1 Torr and 25° C. Since deposition occurs at 0.1 Torrvacuum pressure means free path of the gas molecules is ˜0.1 cm, and thecoating formed is conformal in which the film covers the surface 3dimensionally. Parylene coats front and back surface of the substrates.When only a front side coating is desired, the back side of thesubstrate must be masked. This example describes deposition of thetransparent overcoat 170 as shown in FIGS. 3A and 3B. Differentthicknesses, from 100 Å to 10,000 Å. The parylene coated transparentarticles shown in FIGS. 3 A and B were evaluated in terms of visibletransparency and heat region transparency and mechanical chemicalintegrity. FIGS. 9A, 9B, and 9C show optical performance of somesamples. All coatings are washable, blow dryable and gently cleanablewith a soft cloth. Coating thickness may be modified for cleanable,optically haze free, no absorption conditions.

Measurements:

Sheet resistance of the conductive coating were measure by Surfaceresistivity Meter SMR-232 from Guardian Manufacturing Inc. Spectraltransmission and reflection of the coated samples were measured byPerkin Elmer UV/Vis/NIR spectrophotometer Model Lambda 1050 equippedwith 150 mm WB InGaAs integrating sphere. Infrared spectrel reflectancemeasurement were measured by Perkin Elmer Frontier Optica FTIR (FourierTransformed Infrared) equipment capable to measure from 1.3 to 25 micronregion. Film thicknesses are measured by KLA Tencor Model P-6.

The foregoing description provides embodiments of the invention by wayof example only. It is envisioned that other embodiments may performsimilar functions and/or achieve similar results. Any and all suchequivalent embodiments and examples are within the scope of the presentinvention and are intended to be covered by the appended claims.

What is claimed is:
 1. A transparent article comprising: (a) a substrateadapted for carrying a transparent and electrically conductive thin filmthereon, the thin film including an optical matching, adhesionpromoting, stress releasing layer, a first antireflection layer, a metallayer adapted for infra-red reflection and electrical conductivity, anda second antireflection layer, the substrate layer having a thicknessranging from 1000 Å to 10,000 Å; (b) the optical matching, adhesionpromoting, stress releasing layer is directly on the substrate at athickness ranging from 1000 Å to 10,000 Å; (c) the first antireflectionlayer is directly deposited on the optical matching stress releasinglayer at a thickness ranging from 100 Å to 1000 Å; (d) the metal layeradapted for infra-red reflection and electrical conductivity is directlyand uniformly deposited on the first antireflection layer at a thicknessranging from 50 Å to 400 Å; and (e) the second antireflection layer isdirectly and uniformly deposited on the metal layer adapted forinfra-red reflection at a thickness ranging from 100 Å to 1000 Å,wherein: no layer is positioned between the metal layer adapted forinfra-red reflection and electrical conductivity and the secondantireflection layer, the second antireflection layer comprises W oroxides thereof; and the article has an optical transparency of at least30% between a wavelength ranging from 380 nm to 780 nm and has at least30% solar reflectance at a wavelength ranging from 380 nm to 2200 nm,and the article has an electrical sheet resistance of ranging from 1 to100 Ohm/sq.
 2. The transparent article of claim 1, wherein the firstantireflection layer independently comprises at least one of W or oxidesthereof, Sn or oxides thereof, Ti or oxides or nitrides thereof, Al oroxides thereof, Ta or oxides thereof, Hf or oxides thereof, Nb or oxidesthereof, an indium tin oxide (ITO), Bi or oxides thereof, Ce or oxidesthereof, Pr or oxides thereof, Ni or oxides thereof, an aluminum dopedzinc oxide (AZO), or an indium zinc oxide (IZO).
 3. The transparentarticle of claim 1, wherein the first antireflection layer is WO₃. 4.The transparent article of claim 3, wherein the second antireflectionlayer is WO₃.
 5. The transparent article of claim 4, wherein the metallayer adapted for infra-red reflection and electrical conductivitycomprises at least one of Ag, Au, Ag—Au, Cu, Al, Pd, Pt, Ni, Rd, or Zn.6. The transparent article of claim 5, wherein the metal layer adaptedfor infra-red reflection and electrical conductivity is Ag.
 7. Thetransparent article of claim 6, wherein the substrate is either rigid orflexible.
 8. The transparent article of claim 7, wherein the substratecomprises at least one of glass, a polycarbonate, and a polyethyleneterephthalate.
 9. The transparent article of claim 8, wherein thesubstrate is glass.
 10. The transparent article of claim 8, wherein thesubstrate is polycarbonate.
 11. The transparent article of claim 8,wherein the substrate is polyethylene terephthalate.
 12. The transparentarticle of claim 1, wherein the transparent and electrically conductivethin film maintains, without loss, optical and electrical properties forup to nine years stored at ambient humidity and/or room temperature. 13.The transparent article of claim 12, wherein each of the opticalmatching stress releasing layer, the first antireflection layer, themetal layer, and the second antireflection layer are uniformly depositedin the article.
 14. The transparent article of claim 13, wherein anoutermost protective transparent layer is present in the article. 15.The transparent article of claim 1, wherein the article is an electrode.16. The transparent article of claim 15, wherein the electrode isadapted for use in an electrochromic device.
 17. The transparent articleof claim 1, wherein the article is adapted for adhering to a glasswindow.
 18. The transparent article of claim 17, wherein the articleincludes electromagnetic interference shielding properties having anattenuation of from −10 dB to −45 dB at a frequency of 1 GHz to 100 GHz.19. The transparent article of claim 1, wherein the article is adaptedfor retrofitting onto a glass window.
 20. The transparent article ofclaim 1, wherein the article includes electromagnetic interferenceshielding properties having an attenuation of from −10 dB to −45 dB at afrequency of 1 GHz to 100 GHz and an electrical sheet resistance rangingfrom 1 to 50 Ohm/sq.
 21. The transparent article of claim 1, wherein athird antireflection layer is directly deposited on the secondantireflection layer at a thickness ranging from 100 Å to 1000 Å, thethird antireflection layer made from the same material and havingsubstantially the same thickness as the first antireflection layer; asecond metal layer adapted for infra-red reflection and electricalconductivity is directly deposited on the third antireflection layer ata thickness ranging from 50 Å to 400 Å; and a fourth antireflectionlayer that is directly deposited on the second metal layer adapted forinfra-red reflection at a thickness ranging from 100 Å to 1000 Å, thefourth antireflection layer made from the same material and havingsubstantially the same thickness as the second antireflection layer. 22.The transparent article of claim 1, wherein an outermost protectivetransparent layer is present at a thickness ranging from 500 Å to 5000Å.
 23. The transparent article of claim 22, wherein a thirdantireflection layer is directly deposited on the second antireflectionlayer at a thickness ranging from 100 Å to 1000 Å, the thirdantireflection layer made from the same material and havingsubstantially the same thickness as the first antireflection layer; asecond metal layer adapted for infra-red reflection and electricalconductivity is directly deposited on the third antireflection layer ata thickness ranging from 50 Å to 400 Å; and a fourth antireflectionlayer that is directly deposited on the second metal layer adapted forinfra-red reflection at a thickness ranging from 100 Å to 1000 Å, thefourth antireflection layer made from the same material and havingsubstantially the same thickness as the second antireflection layer. 24.The transparent article of claim 1, wherein a third antireflection layeris directly deposited on the second antireflection layer at a thicknessranging from 100 Å to 1000 Å, the third antireflection layer made fromthe same material and having substantially the same thickness as thefirst antireflection layer; a second metal layer adapted for infra-redreflection and electrical conductivity is directly deposited on thethird antireflection layer at a thickness ranging from 50 Å to 400 Å;and a fourth antireflection layer that is directly deposited on thesecond metal layer adapted for infra-red reflection at a thicknessranging from 100 Å to 1000 Å, the fourth antireflection layer made fromthe same material and having substantially the same thickness as thesecond antireflection layer.
 25. The transparent article of claim 24,wherein an outermost protective transparent layer is deposited on thefourth antireflection layer at a thickness ranging from 100 Å to 10,000Å.
 26. The transparent article of claim 1, wherein an outermostprotective transparent layer is deposited on the second antireflectionlayer at a thickness ranging from 100 Å to 10,000 Å.
 27. A method ofpreparing a transparent article, the method comprising: (a) providing asubstrate adapted to carry a transparent and electrically conductivethin film thereon, the thin film including an optical matching stressreleasing layer, a first antireflection layer, a metal layer adapted forinfra-red reflection and electrical conductivity, a secondantireflection layer, and an optional transparent outermost protectivetransparent layer, the substrate layer having a thickness ranging from1000 Å to 10,000 Å; (b) depositing the optical matching stress releasinglayer directly on the substrate at a thickness ranging from 1000 Å to10,000 Å; (c) depositing the first antireflection layer directly on theoptical matching stress releasing layer at a thickness ranging from 100Å to 1,000 Å; (d) depositing the metal layer adapted for infra-redreflection and electrical conductivity directly deposited on the firstantireflection layer at a thickness ranging from 50 Å to 400 Å; and (e)depositing the second antireflection layer directly on the metal layeradapted for infra-red reflection at a thickness ranging from 100 Å to1000 Å thereby forming the transparent article, wherein: no layer ispositioned between the metal layer adapted for infra-red reflection andelectrical conductivity and the second antireflection layer, thetransparent and electrically conductive thin film maintains, withoutloss, optical and electrical properties for up to nine years when storedat ambient humidity and/or room temperature, and the secondantireflection layer comprises W or oxides thereof, and the article hasan optical transparency of at least 30% between a wavelength rangingfrom 380 nm to 780 nm and has at least 30% solar reflectance at awavelength ranging from 380 nm to 2200 nm, and the article has anelectrical sheet resistance of ranging from 1 to 100 Ohm/sq.
 28. Themethod of claim 27, further comprising step (f) depositing an outermostprotective transparent layer on the second antireflection layer at athickness ranging from 100 Å to 10,000 Å.
 29. The method of claim 27,wherein at least one of the layers deposited during steps (b)-(e) isdeposited by sputtering deposition.
 30. The method of claim 29, whereineach layer deposited during steps (b)-(e) is deposited by sputteringdeposition.
 31. The method of claim 27, wherein at least one of thelayers deposited during steps (b)-(e) is deposited by electron beam(e-beam) deposition.
 32. The method of claim 31, wherein each layerdeposited during steps (b)-(e) is deposited by e-beam deposition.